At the center of that push is a new proposal by Sen. David Frockt, D-Seattle, which was introduced last week and got a public hearing on Tuesday. The bill would raise the purchase age for semi-automatic rifles and some modified shotguns from 18 to 21, and require more rigorous background checks for buyers of those firearms. The bill also includes Republican priorities to improve school safety.

“I will work with members of both parties to improve and perfect this legislation to make our schools and our communities safer,” Frockt said in prepared remarks.

Bump stocks came into public consciousness when a gunman used them last fall to kill 58 people at an outdoor Las Vegas concert. Senate lawmakers last month originally approved the bill, but the House amended it to allow the Washington State Patrol to set up a “buy back” program for people who already own the devices. Tuesday’s vote adopted the updated House bill.

Starting July 1, the bill would make it illegal for anyone in Washington to manufacture or sell bump stocks. Then, in July 2019, it would become illegal to own or possess a bump stock in the state.

And in recent years, firearms bills have often stalled at the Legislature, even as voters strongly approved gun-related ballot measures in 2014 and 2016.

In Olympia, many Republicans have criticized gun-regulation proposals as poorly written or infringing upon constitutional rights.

Some proposals this year failed to advance, including Frockt’s original bill — which was requested by the Attorney General’s Office — to strengthen gun-purchase background checks for so-called assault rifles.

Senate bill 6620, Frockt’s new proposal, revives a version of that plan and rolls it into a more expansive proposal to address guns and school safety.

SB 6620 would require buyers of semi-automatic rifles and some modified shotguns to go through the more rigorous background-checks process currently used for people purchasing pistols.

The bill raises the purchase age for those other guns to 21, the current legal age to purchase a pistol.

Frockt’s bill also includes a provision to implement a response system with the goal of helping law enforcement deal with school emergencies more quickly. Sen. Ann Rivers, R-La Center, had originally proposed that provision in unrelated legislation.

SB 6620 also pulls from HB 2442, sponsored by Rep. Matt Manweller, R-Ellensburg, to allow students to report threats anonymously through technology such as mobile apps.

In a text message, Manweller wrote that he was disappointed Frockt attached the Republican’s proposal “to a gun control bill.”

On Tuesday morning, advocates for gun regulations — along with some gun-rights proponents — flooded the Senate Ways and Means Committee to give input into Frockt’s new proposal.

The National Rifle Association’s lobbyist and other gun-rights advocates opposed the parts of the bill dealing with purchase age and background checks.

They argued the provisions are an infringement on the Second Amendment rights of people legally allowed to own rifles.

On the other side, students from Seattle’s Ingraham High School skipped school to attend the hearing and advocate for the bill.

“I’m willing to lose a day of learning to be able to fight for someone else’s life,” said Alicia Heia, an 18-year-old senior at the high school.

Heia and others at the hearing said they planned to attend next month’s March For Our Lives gathering and she said she felt Frockt’s bill was a comprehensive approach to addressing school safety.

Since the 1999 Columbine shooting, 150,000 students across the nation have been exposed to a school shooting, according to an analysis by The Washington Post.